Railway-traffic-controlling apparatus



L. V. LEWIS. RAILWAY TRAFFlC CONTROLLING APPARATUS. APPLICATION FILED APR. I6, um. RENEW-ED 92c. 21, 1919.

2 SHEElS-SHEEI 1- LOW SPEED S! llm w w Q E" i g 8 *ITNES INVENTOR k Z? L. M1

source other than the track rails.

UNITED STATES PATENT OFFICE.

LLOYD V. LEWIS, OF EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, 01 SVJ-ISSVALE, PENNSYLVANIA, A GOR- PORATION OF PENNSYLVANIA.

RAILWAY-TRAFFIC-GONTROLLING APPARATUS.

Application filed A' rn 16, 1917, Serial No. 182,262. Renewed December 27, 1919.

To all whom it may concern:

Be it known that I, LLoYD V. LEwIs, a citizen of the United States, residing at Edgewood borough, in the county of Alleghcny and State of Pennsylvania,ha've invented certain new and useful Improvements in Railway-Traiiic-Coi1tr0lling Apparatus, of which the following is a specification.

My invention relates to railway t'raffic controlling apparatus, and particularly to apparatus for imposing certain speed limitations on railway cars or trains in accordance with tr'aflic conditions in advance.

I will describe one form of system embodying my invention and will then point out the novel features thereof in claims.

In the accompanying drawings, i igure l is a diagrammatic view showing one form of trackway apparatus which may be employed in a system embodying my invention. Fig. 2 is a diagrammatic View showing one form of vehicle-carried apparatus which may be employed in combination with the trackway apparatus shown in Fig.1 to form a system embodying my invention.

Similar reference characters refer to similar parts in each of the views.

Referring first to Fig. 1, the reference characters R, R- designate the track rails of a railway over which traffic normally moves in the direction indicated bv the arrow. These track rails are divided into sections AB, B C, etc, in any suitable manner, such, for example, as by insulated joints 2, and each such section is provided with a track circuit comprising means for supplying signaling current to the track rails and a track relay receiving such current from the rails.

As here shown, the track relays, which are designated 1, are of the two-phase motor type, each comprising a rotor member 3 which is operatively connected with the circuit controlling contacts, a winding 4 connected directly with the rails of the corresponding section, and a second winding'5 supplied with alternating current from a A 'i This means for supplying signaling current to each track section comprises, in the form here shown, a transformer T whose secondary is connected with the track rails of the section and whose primary is connected at Specification of Letters Patent.

Patented July 20, 1920.

Serial No. 347,838.

times with a source of 90 cycle current and at other times with a source of 60 cycle current, the frequency of the current which is thus supplied to the transformer of each section being determined by a contact 6 of the track relay for the section next in advance. That is, when contact 6 is in engagement with the upper contact point due to the relay being energized, 90, cycle current is supplied to the track transformer of the section in the rear, but when this contact is down, due to the relay being deenergized, 60 cycle current is supplied to the track transformer of the section in the rear.

At this point I desire to point out that in order to simplify the drawings, I have not shown complete circuits throughout, but have in certain instances shown only the portions of the circuits which pass through the apparatus included in the drawings, and when the current is alternating l have indicated at one end of each circuit the frequency of the current which is supplied thereto.

The circuit for winding 5 of each track relay P is controlled by a contact 8 of a line relay L in such manner that this winding is supplied with 90 cycle or 60 cycle current according as relay L is energized or denergized. Relay L is in turn controlled by a contact 7 of the track relay P for the section in advance, so that relay L is energized or deenergized according as the relay P which controls it is energized or deenergized.

Each relay i will respond by closing its front contacts when both windings thereof are energized by 90 cycle current, and also when both windings are energized by 60 cycle current.

From the foregoing it will be clear that when a track section is occupied by a car or train, the track relay for such section will be declnergized; both windings of the track relay for the section next in the rear will be supplied with current at 60 cycles so that such relay will be energized; and both windings of the track relay for the second section in the rear of the occupied section will be supplied with 90 cycle current so that such relay will likewise be energized. For purposes of my present invention it is impor tant to note that the rails of all track sections in the rear of an occupied section are supplied with 90 cycle current except the section immediately in the rear of the occupied section, and this is supplied'witlfGO cycle inedia-tely in advance ofthe signal is 00-' cupied, caution when the section immediately in advance of the signal is unoccupied and the next section in advance is occupied, and p'roceed".vhen two or more 'sectionsimmediately in advance of the signal are unoccupied. Inasmuch as the circuits which control these signals form no part of my invention, they are omitted from the drawing.

Located at certain points in the trackway are short conductors K,which may, for ex ample, be short lengths of rail. Each of these conductors is at times supplied with 90 cycle current by means of a transformer 9 the secondary of which is connected with two points on the conductor and the primary of which is connected with a source of 90 cycle current through back contacts of relays P and L of the section in which the conductor is located. These contacts are designated 65 and (36, respectively. Consequently, when both 0 fthese relays are deenergized, 90 cycle current will flow through the conductor or conductors Kill the corresponding section. The location and function of these conductors will appear hereinafter.

Referring now to Fig. 2, the reference character 10 designates a box in which is journaled a shaft 11. This shaft carries at its outer end a spur gear 16 which is connected through suitable gearing including a gear 12, with a wheel or axle of the vehicle, so that while the vehicle is in motion the shaft 11 is constantly rotated at a speed proportional to the speed of the vehicle. Attached to the inner end of shaft 11 is a yoke 13 in the arms of which are pivoted the two bell cranks 14 and 1 1 of a centrifuge. These bell cranks coact with a head 15 freely mounted on a longitudinally movable stem 17 which passes freely through the shaft 11. Head 15 coacts with another head 1.) fixed to stem 17, the two heads being separated by a ball bearing to reduce friction. Suitable means are provided, as hereinafter described, for biasing stem 17 to the right, thus opposing the natural tendency of the centrifuge to open while the vehicle is in motion. The right hand end of stem 17 constitutes a valve 18 which controls the vehicle brakes in any suitable manner, the control being such that the brakes are applied. when the valve is opened. When the centrifuge is closed the valve 18 is closed, but when the centrifuge opens it moves the stem 17 to the left and so opens valve 18.

hour, the centrifuge will not open.

end of a spring 20. The other end of this spring rests against a piston2l which is adapted to rec procate 1n a cylinder 22.

The spring is so "adjusted that when the pisten 21 is at the left-hand end of its cylinder,

as shown in the drawing, the pressure exerted on stem .17 by the spring is of such value that when the vehicle does not exceed a fixed low speed, for example, 15 miles per This spring, then, when fully expanded as shown, imposes'on the vehicle what I will term a low speed limit. 7

23 designates a pipe for at times admitting'fluid pressure to the cylinder 22 on the 20 and so greatly increasing the pressure ex- This erted by-this spring on the rod 19. pressure is such as to permit the vehicle to travel at a speed not exceeding a fixed high value, for example, 60 miles per hour, without opening the centrifuge, and so it imposes what I will term a high speed limit.

For reasons which will appear hereinafter, it is desirable to provide'for imposing on the vehicle a Fmedium speed limit, such as 35 miles per hour, and to do this I provide means for compressing spring 20 to an intermediate point. As here shown, this means comprises a second pisto'n 241 working in a cylinder 25 and having a piston rod 24* which abuts against piston 21. Piston 2 1 is normally held at the left-hand endof its cylinder by a light spring 27, in which position it does not interfere with the operation of piston 21. hen, however, fluid pressure is admitted to cylinder 25 through a pipe 26, piston 24: is forced to the right, thus moving piston 21 and compressing spring 20. The length of cylinder 25 is such that piston 21 is moved through only a part of its travel by piston 24, so that spring 20 is compressed to such degree as to give the desired medium speed limit.

Fluid pressure, usually air, is at times supplied to pipe 23 from a reservoir or other suitable source, this supply being controlled by a valve 29 which in turn is controlled by a-magnet H which I will term the high speed magnet. This magnet and valve are so arranged that when the magnet is deenergized' the valve disconnects the source of pressure from pipe 23 and connects the latter with atmosphere, but that when the magnet is energized the valve connects the pipe 23 with the source of pressure.

The supply of fluid pressure to pipe 26 is controlled in a similar manner by a valve 30 and a magnet M, which latter I will term the medium speed magnet.

High speed magent H is provided with a circuit which is controlled by a front contact 31 of a relay D, so that this magnet is ener ized onl when the rela' is ener ized. D b

Relay D is in turn provided with a circuit including the secondary of a transformer E, the primary of which is energized by means which I will now explain.

The vehicle is provided with a circuit a which receives. energy from the track rails R, R. This circuit includes two coils 32 and 32 which are wound on iron cores 33 and 33, which cores are mounted on the vehicle in front of the foremost wheels and in inductive relation to the track rails R, B, respectively.

Inasmuch as the current which is received in this circuit a is very feeble and therefore unsuitable to operate the relay D directly, I interpose between the circuit and the transformer E a current amplifying device G. This device comprises a vacuum tube or bulb 34, in which is mounted a filament 37 preferably of tungsten, a metallic plate 35, and a metallic grid 36 interposed between the filament and the plate. The filament 37 is constantly heated by a battery 38. The plate 35 and the filament 37 are connected with the terminals of a circuit which includes the primary of transformer E and a battery 39. The circuit a is connected with the filament 37 and the grid 36, and a condenser 40 is connected across these two latter elements. The circuit a is tuned to resonance to current of a frequency of 90 cycles. Current of this frequency in this circuit produces, therefore, an alternating difference of potential on the grid 36, which serves to increase and decrease the rate of emission of electrons from the filament 37, and consequently produces corresponding variations in the strength of the current. flowing in the circuit of the primary of the transformer E. The current thus induced in the secondary of transformer E is of sufficient amplitude to operate relay D, which relay, owing to the tuning of circuit a, responds to 90 cycle current in the track rails, but not to 60 cycle current.

Also located on the vehicle is asoft iron core 33 carrying a winding 32, which winding is included in a vehicle-carried circuit a, which circuit is associated with an amplifier G, similar to amplifier G. This amplifier G serves to create alternating currents in the circuit of the primary of a transformer E, the secondary of which is directly connected with arelay D.

Relays D and D control a slow-acting device J which is adapted to change from an initial condition to an ultimate condition traveled by the vehicle.

in a given interval. In the form here shown, the interval is an interval of distance The device comprises a contact 41 which is controlled by a piston 42 working in a cylinder 43. Contact 41 is biased to the open position by a spring 44, but may be moved to the closed position in opposition to this spring by fluid pressure in a reservoir N when this pressure is sufficiently high. Reservoir N is connected with a source of fluid pressure or with a pipe 45, according as a slide valve 46 is in one position or the other, and this slide valve is in turn operated by a piston 47 working in a cylinder 48. Piston 47 is normally held in the position in which it is shown by fluid pressure acting on its righthand face in opposition to a spring 52. The left-hand face of this piston may, however, be connected with atmosphere or with a source of fluid pressure by a valve 51 which in turn is controlled by an electromagnet Q. hen this magnet is deenergized, the left-hand face of piston 47 is connected with atmosphere through a port 67, so that the piston occupies the position in which it is shown whereby reservoir N is connected with pipe 45. When, however, magnet Q is energized, valve 51 admits fluid pressure to the left-hand face of piston 47, thereby equalizing the fluid pressure on the two sides of piston 47 and permitting the spring 52 to drive piston 47 to the right. Valve 46 then connects reservoir N with the source of pres sure.

Pipe 45 is connected with a valve device 49 whereby, when this pipe is open to reservoir N, the pressure in the latter will be decreased in proportion to the distance traveled by the vehicle. Valve 49 is of a rotary type and is operatively connected with an axle of the vehicle though means including a worm 54. This valve, as it rotates, alternately connects a small reservoir N with pipe 45 and with atmosphere, so that a pocket of air is allowed to escape from reservoir N at each revolution of valve 49. The rotary .valve is held against its seat by pressure taken from pipe 45 through a pipe 69.

The slow-acting device J is so designed that when reservoir N is subject to full pressure, contact 41 is closed, and that if magnet Q is then deenergized, this contact will open after the vehicle has traveled a certain distance, such, for example, as 3000 feet.

Magnet Q, of the slow-acting device is controlled by relay D, the circuit being from a source of current through contact 57 of this relay, wires 58 and 59. magnet Q. back to the source of current. Magnet Q will consequently be energized as long as relay D is energized, so that the slow-acting device is then retained in its initial condition. When relay D becomes deenergized,

the control of magnet Q is transferred to relay D, the circuit then being from a source of current through contact 41 of slow-acting device J, wire 61, back contact GS of relay D, front contact 56 of relay D, wire 59, magnet Q, back to the source of current. Hence, if relay D is momentarily energized after relay D becomes deenergized and before contact 41 opensthe slow-acting device J will be restored to its initial condition and will thereupon again begin its change toward ultimate condition.

The medium speed magnet M.- is controlled by relay D and by contact 41 of the slow-acting device J, the circuit being from a source of current through contact 41,

wire 61, back contact 55 of relay D, wire 62, magnet M, back to the source of current. This magnet I will consequently be energized when relay D is deenergized and contact 41 is closed. At such times the high speed magnet I1 is, of course, deenergized.

Referring again to Fig. 1, the line 63 is a curve indicating, by its distance above the zero speed line 64, the speed at which a ve-.

hicle may proceed at all points under the traflic conditions shown in the drawing, that is, when the section immediately in advance of point C is occupied by a vehicle IV so thatthe signal S for that section indicates stop, the signal S for section BC indicates caution, and the signal S for section A-B indicates proceed.

Assuming now that a second vehicle IV, equipped with the apparatus shown in Fig. 2, approaches vehicle W, the operation is as follows:

As vehicle W enters section AB, circuit a on the vehicle receives 90 cycle energy from the track rails so that relay D is energized. Magnet II is also energized, so that fluid pressure is admitted directly behind piston 21, whereby the vehicle may travel through section A-B at the high speed of 60 miles per hour without incurring an application of the brakes. Magnet Q is also energized so that the slow-acting device J is held in its initial condition.

The rails of section B-C are carrying 60 cycle current because relay P of the section in advance of G is deenorgized, and while relay P of section B-C responds to this current, still relay D on the vehicle does not respond thereto. Consequently, when the vehicle enters section BC, relay D opens thereby deenergizing high speed magnet I so that fluid pressure is removed from the left-hand face of piston 21. Medium speed magnet M immediately becomes energized, however, so that the medium speed of 35 miles per hour is imposed on the vehicle. If the speed is above this value as the vehicle enters section B 0, valveylS will be opened and will remain open until the speed is reduced to miles per hour whereupon it will close. The opening of relay D deenergizes magnet Q, so thatthe slow-acting device J begins to change toward its ultimatecondition. The vehicle may then proceed at the medium speed of 35 miles per hour until contact 41 opens, which'will occur when the vehicle has progressed 3000 feet into the section, that'is, to the point marked X, unless the slow-acting device J is in the meantime restored. This restoration willoccur if the vehicle passes over a conductor K before contact 41 opens, and in this event the slow-acting device J will be restored to its initial condition so that the vehicle may then travel another interval of 3000 feet from conductor K, or to the point marked X, before contact 41 will open. \Vhen this finally occurs, magnet M will be deener ized so that the low speed of 15 miles per hour will be imposed, whereupon the speed will be reduced to this value by valve 18 and the vehicle may then proceed at such speed.

It will be observed that when the vehicle IV enters the section in the rear of an occupied section, it is permitted to travel at a medium speed for at least the distance required for the slow-acting device to reach its ultimate condition, that is, for contact 41 to open. I have stated that this distance may be 3000 feet, but this should be qualified by the further statement that for a given installation this distance is such that in the .shortest section the contact 41 will open at such point that the low speed limit will be imposed a suiiicient distance in the rear of the exit end of the section to insure that the speed will be reduced to the low value when the vehicle reaches the exit end of the section. Then for longer sections one or more conductors K may be provided for restoring the slow-acting device, the last of such conductors being located at a distance from the exit end of the section equal to the distance interval of the slow-acting device plus the distance required to reduce the speed of vehicles fromv the medium value to the low value.

It will be seen, therefore, that apparatus embodying my invention requires that when a vehicle passes'a signal indicating caution, the speed shall be reduced to a medium value, which value may then be maintained until such point is reached that further'reduction must begin in order to bring the vehicle to the low speed limit when or before the stop signal is reached. This, I have found, is in accordance with the method of train operation which has been demonstrated by certain roads to be the most satisfactory.

. Although I have herein shown and described only one form of apparatus embodying my invention, itis understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit andscope of my invention.

Having thus described my invention, what I claim is: F r

l. A railway traffic controlling system comprising apparatus on a vehicle for imposing a high speed limit, a medium speed limit, or a low speed limit, trackway means for rendering said apparatus effective to impose the high speed limit, a slow-acting device for rendering said apparatus effective to impose the medium speed limit during a limited interval after said traekway means ceases to be effective, and means located in the trackway for resetting said slow-acting device to'continue the medium speed limit, the said apparatus acting to impose the low speed limit after the slow-acting device ceases to be effective.

2. A railway traffic controlling system comprising apparatus on a vehicle for imposing a high speed limit, a medium speed limit, or a low speed limit, trackway means for rendering said apparatus effective to impose the high speed limit, and a slow-acting device on the vehicle for rendering said apparatus effective to impose the medium speed limit during a limited interval after said trackway means ceases to be effective, said apparatus operating to impose the low speed limit after said slow-acting device ceases to be effective.

3. A railway traffic controlling system comprising apparatus on a vehicle for imposing three fixed speed limits, means on the vehicle for rendering said apparatus effective to impose the high speed limit, trackway means for controlling said means, a slow-acting device on the vehicle for rendering said apparatus effective to impose the medium speed limit during a limited interval after said first means becomes ineffective, said apparatus acting to impose the lowest speed limit after said-slowacting means becomes ineffective, and means located in the trackway for resetting said slow-acting device to continue the medium speed limit.

4. A railway traffic controlling system comprising a slow-acting device on a vehicle, vehicle governing apparatus controlled by said device for imposing a fixed medium speed limit during the interval required for said device to operate and for imposing a low speed limit after the expiration of such interval, means located in the trackway for resetting said d vice to its initial condition to continue the medium speed limit, and other trackway means for holding said device in its initial condition and removing said vehicle governing apparatus from controi by said slow-acting device to permit movement of the vehicle at a speed higher than said medium speed.

5. A railway traffic controlling system comprising a slow-acting device on a vehicle, vehicle governing apparatus controlled by said device for imposing fixed speed limit during the interval required for said device to operate, and trackway means for holding said device in its initial condition and removing said vehicle e overning apparatus from control by said device to permit progress of the vehicle at a speed higher than said fixed value.

6. A railway traffic controlling system comprising a slow-acting device on a vehicle, vehicle governing apparatus controlled by said device for imposing a fixed speed'liniit during the interval required for said device to operate, means on the vehicle for removing said governing means from control by said device and for holding said device in. its initial condition, and trackway means for controlling said last-mentioned means.

7. A railway traffic controlling system comprising a slow-acting device on a vehicle arranged to change from an initial condition to an ultimate condition within a given distance traveled by the vehicle, vehiclegoverning apparatus controlled by said device for imposing a fixed speed limit throughout the distance in which said device is changing, means located in the trackway for restoring said device away from its ultimate condition to continue the medium speed limit, and trackway means for holding said device in its initial condition and removing said vehicle-governing apparatus from control by said device to permit travel of the vehicle at a speed higher than said fixed speed.

8. A railway trafiic controlling system comprising track rails, means for supplying alternating signaling current thereto, a air-- cuit on a vehicle receiving signaling energy from said rails, a slow-acting device on the vehicle set into operation upon the failure of signaling current in said circuit, means located in the trackway for restoring said device, and vehicle-governing means controlled by said circuit and by said device.

9. Railway traflic controlling apparatus comprising a high speed magnet and a medium speed magnet carried by a vehicle, means controlled from the trackway for energizing said high speed magnet, a slowacting device on the vehicle arranged to change from an initial condition to an ultimate condition within a fixed interval, means controlled by said slow-acting device while changing for energizing said medium speed magnet, means for holding said slow-acting device in its initial condition while the high speed magnet is energized, means located at intervals in the trackway mittent. trackwaymeans for restoring the for restoring said slow-acting device when the high speed magnet is deenergized, and

vehicle governing means controlled by said magnets for imposing a highspeed limit when the high speed magnet is energized, a medium speed limit when the medium speed magnetonly is energized, and a low speed limit when both magnets are denergized.

10. A railway trafiic controlling system comprisinga run-down device on a vehicle, traekway controlled means for holding the run-down device in its initial position, interrun-down device to its initial position, and means controlled by the run-down device for limiting the speed of the vehicle.

'11. A railway traflic controlling system comprising means for limiting the vehicle speed to an intermediate value,rmeans for limiting the'speed to a lower value after the vehicle has traversed a predetermined dis tance, trackway controlled means for holding both said means ineffective, and means for intermittently restoring said second" means to its initial condition.

In testimony whereof 1 affix my signature in presence of two Witnesses.

LLOYD V. LEWIS.

WVitnesses: 1

' A. HERMAN WEGNER,

FAY GLA'seoW. 

